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The current study was designed to determine the relationship between tracheobronchial and respirable dust exposures in coal miners. Particle size distributions in underground mining jobs at four coal mines were assessed so that the job specific respirable and tracheobronchial dust fractions could be estimated. The historical respirable dust measurements were then converted into estimates of tracheobronchial dust exposures. The four bituminous mines studied were in Western Pennsylvania, Kentucky, and Maryland. A total of 180 samples was analyzed, 142 from face occupations and 38 from nonface jobs. The results of the analysis indicated that it was not possible to distinguish the particle size distributions between specific occupations or groups of occupations. It appeared that the variability in distributions may be greater between mines than between occupations within the mine. The authors conclude that it was not possible to reconstruct historical particle size specific distributions for a large cohort of miners, including work in multiple mines, without extremely extensive particulate distribution sampling in the mines. However, this does not mean that measurement of thoracic fraction exposure is equivalent to respirable measurements and is without merit. The authors suggest that occupation specific tracheobronchial dust exposures would be highly correlated with historically collected respirable exposures. The exposure response analyses using these two measures would probably be similar.